The present invention relates to a process for coloring olives, in particular using an aqueous erythrosine solution.
It is known that erythrosine (3',6'-dihydroxy-2',4',5',7'-tetraiodospiro(isobenzofuran-1(3H),9'-(9H)xan thene)-3-one sodium salt) can be used to color foodstuffs and pharmaceuticals without harmful effects (Colour Index vol. 4 (edition 3, 1971), page 4428). It is a brown powder which dissolves in water producing a cherry-red solution. However, in the foodstuffs coloring sector, it has been noticed that certain parameters and conditions must be respected to prevent the finished product having a patchy appearance, that is to say, an uneven color, or to prevent it losing its color after a brief period of time, or during storage or when rubbed, for example, with a cotton pad soaked in water.
It has been noticed that if olives are colored using erythrosine, by simply immersing them in a solution of variable concentration, the treated olives have a patchy "leopard skin" appearance, that is to say, they are both red (due to the erythrosine) and green (due to the natural chlorophyll) or the color of the olives treated.